Abseil - C++ Common Libraries
The repository contains the Abseil C++ library code. Abseil is an open-source collection of C++ code (compliant to C++14) designed to augment the C++ standard library.
Table of Contents
About Abseil
Abseil is an open-source collection of C++ library code designed to augment the C++ standard library. The Abseil library code is collected from Google's own C++ code base, has been extensively tested and used in production, and is the same code we depend on in our daily coding lives.
In some cases, Abseil provides pieces missing from the C++ standard; in others, Abseil provides alternatives to the standard for special needs we've found through usage in the Google code base. We denote those cases clearly within the library code we provide you.
Abseil is not meant to be a competitor to the standard library; we've just found that many of these utilities serve a purpose within our code base, and we now want to provide those resources to the C++ community as a whole.
Quickstart
If you want to just get started, make sure you at least run through the Abseil Quickstart. The Quickstart contains information about setting up your development environment, downloading the Abseil code, running tests, and getting a simple binary working.
Building Abseil
Bazel and CMake are the official build systems for Abseil. See the quickstart for more information on building Abseil using the Bazel build system. If you require CMake support, please check the CMake build instructions and CMake Quickstart.
Support
Abseil follows Google's Foundational C++ Support Policy. See this table for a list of currently supported versions compilers, platforms, and build tools.
Codemap
Abseil contains the following C++ library components:
base
Thebase
library contains initialization code and other code which all other Abseil code depends on. Code withinbase
may not depend on any other code (other than the C++ standard library).algorithm
Thealgorithm
library contains additions to the C++<algorithm>
library and container-based versions of such algorithms.cleanup
Thecleanup
library contains the control-flow-construct-like typeabsl::Cleanup
which is used for executing a callback on scope exit.container
Thecontainer
library contains additional STL-style containers, including Abseil's unordered "Swiss table" containers.crc
Thecrc
library contains code for computing error-detecting cyclic redundancy checks on data.debugging
Thedebugging
library contains code useful for enabling leak checks, and stacktrace and symbolization utilities.flags
Theflags
library contains code for handling command line flags for libraries and binaries built with Abseil.hash
Thehash
library contains the hashing framework and default hash functor implementations for hashable types in Abseil.iterator
Theiterator
library contains utilities for augmenting ranges in range-based for loops.log
Thelog
library containsLOG
andCHECK
macros and facilities for writing logged messages out to disk,stderr
, or user-extensible destinations.memory
Thememory
library contains memory management facilities that augment C++'s<memory>
library.meta
Themeta
library contains compatible versions of type checks available within C++14 and C++17 versions of the C++<type_traits>
library.numeric
Thenumeric
library contains 128-bit integer types as well as implementations of C++20's bitwise math functions.profiling
Theprofiling
library contains utility code for profiling C++ entities. It is currently a private dependency of other Abseil libraries.random
Therandom
library contains functions for generating psuedorandom values.status
Thestatus
library contains abstractions for error handling, specificallyabsl::Status
andabsl::StatusOr<T>
.strings
Thestrings
library contains a variety of strings routines and utilities, including a C++14-compatible version of the C++17std::string_view
type.synchronization
Thesynchronization
library contains concurrency primitives (Abseil'sabsl::Mutex
class, an alternative tostd::mutex
) and a variety of synchronization abstractions.time
Thetime
library contains abstractions for computing with absolute points in time, durations of time, and formatting and parsing time within time zones.types
Thetypes
library contains non-container utility types, like a C++14-compatible version of the C++17std::optional
type.utility
Theutility
library contains utility and helper code.
Releases
Abseil recommends users "live-at-head" (update to the latest commit from the master branch as often as possible). However, we realize this philosophy doesn't work for every project, so we also provide Long Term Support Releases to which we backport fixes for severe bugs. See our release management document for more details.
License
The Abseil C++ library is licensed under the terms of the Apache license. See LICENSE for more information.
Links
For more information about Abseil:
- Consult our Abseil Introduction
- Read Why Adopt Abseil to understand our design philosophy.
- Peruse our Abseil Compatibility Guarantees to understand both what we promise to you, and what we expect of you in return.